Return to Technical Hiring Guide Middle-Tier Engineer 
Middle-tier engineer roles are less common (it is much more common to have back-end engineers that work in the middle tier), but can be found in larger companies or teams working with large-scale software. Like back-end engineers, they also don’t work on the user interface and instead are focused on being the glue between the back-end and front-end parts of the system. Typically middle-tier engineers are responsible for the core of the business logic. If software were a grocery store, back-end engineers would get the stock off the trucks, and middle-tier engineers would make sure that the right amount of items were put in the right place. That middle-end logic makes it not just a room full of groceries, but a system of groceries organized to make a proper grocery store. Generally the skills required for a middle-tier engineer overlap most with a back-end engineer, but the back-end engineer may have a bit more responsibility for the system or data storage of an application. Questions for Middle-Tier Engineers:
Middle-tier engineer roles are less common (it is much more common to have back-end engineers that work in the middle tier), but can be found in larger companies or teams working with large-scale software. Like back-end engineers, they also don’t work on the user interface and instead are focused on being the glue between the back-end and front-end parts of the system. Typically middle-tier engineers are responsible for the core of the business logic. If software were a grocery store, back-end engineers would get the stock off the trucks, and middle-tier engineers would make sure that the right amount of items were put in the right place. That middle-end logic makes it not just a room full of groceries, but a system of groceries organized to make a proper grocery store. Generally the skills required for a middle-tier engineer overlap most with a back-end engineer, but the back-end engineer may have a bit more responsibility for the system or data storage of an application. Questions for Middle-Tier Engineers:
- Q: In your experience, what have been the responsibilities that separated back, middle, and front? A: By diving into their own experience, you gain insight into how work was separated, and how they interfaced with other workers. This is also a great way to understand if they veer more toward a back-end or front-end role, since most people in middle roles tend to lean one way or the other. Expand your questions to see how they worked with other engineers and collaborated on projects. .
- Q: What is a cache? What are some examples of caches you have used? A: This is a great technical question that is easy for recruiters to ask. A cache is simply a place to store data that is faster to retrieve than the source. For example, your fridge is a cache for the goods at the grocery store. You can’t store as much, but it is much faster to retrieve items from the fridge than from the grocery store. Hopefully candidates give you their own examples so the more times you ask this, the better you understand it.